Chair seat and back structure

ABSTRACT

A chair seat and back structure includes a loop-shaped part with a space encompassed by an inner edge thereof, and an elastic covering part; the loop-shaped part has a curvature and a loop-shaped holding groove near to a circumferential edge thereof; the covering part positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part; therefore, the covering part will be changed in the shape by the sitter&#39;s body curvature, and the sitter&#39;s body will touch the chair with increased area.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chair seat and back structure, more particularly one, which makes the chair more comfortable to sit on.

2. Brief Description of the Prior Art

In order for allowing people to sit on chairs for a long period of time, chair seats and backs are usually formed with convexities and concavities according to ergonomics.

Referring to FIGS. 1 and 2, a currently existing chair seat and back structure includes a board-shaped basic part 41, a foam part 42, and a piece of cloth 43. The board-shaped basic part 41 has a proper curvature, and it can be plastic or alternatively it can be wooden. The foam part 42 is stuck on the board-shaped basic part 41, and the cloth 43 is stuck on the foam part 42 and secured to the board-shaped basic part 41.

The chair seat and back structure is found to have the following disadvantages:

1. When a person is seated on the chair, the foam part will be compressed owing to the sitter's body weight, and the sitter's body will feel the board-shaped basic part, which is relatively hard, even if the foam part is somewhat soft and elastic. Consequently, the sitter will have bad blood circulation and feel numbness and pain after having been seated on the chair for a long period of time.

2. The sitter will feel hot and uncomfortable after having been seated on the chair for an extended period of time because air can't travel through the seat and the back.

3. It will take relatively much time and labor to make the board-shaped basic part curve smoothly if the board-shaped basic part is wooden. Furthermore, wooden materials are relatively expensive.

SUMMARY OF THE INVENTION

It is a main object of the present invention to provide an improvement on a chair seat and back structure to overcome the above-mentioned problems. The seat and back structure of the invention includes a loop-shaped part with a space encompassed by an inner edge, and an elastic covering part. The loop-shaped part has a curvature and a loop-shaped holding groove near to a circumferential edge thereof. The covering part is positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part. Therefore, the covering part will be changed in the shape by the sitter's body curvature, and the sitter will be comfortably supported on the chair, with his body touching the seat and back structure with increased area.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood by referring to the accompanying drawings, wherein:

FIG. 1 is a lateral sectional view of the currently existing structure,

FIG. 2 is a rear perspective view of the currently existing structure,

FIG. 3 is a lateral sectional view of the present invention,

FIG. 4 is a partially exploded perspective view of the invention,

FIG. 5 is a lateral sectional view of the first preferred embodiment in the present invention, and

FIG. 6 is a lateral sectional view of the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 3 to 5, a first preferred embodiment of a chair seat and back structure in the present invention includes a loop-shaped part 1, and a covering part 2.

The loop-shaped part 1 has a proper curvature and a loop-shaped holding groove 12 near to a circumferential edge thereof, and it is preferably made of plastic by means of injection molding. And, a space 11 is encompassed by an inner edge of the loop-shaped part 1.

The covering part 2 is secured over the loop-shaped part 1, and it includes an inner covering sheet 21, a foam part 22, and an outer covering sheet 23, which foam part 22 can be made of foam rubber. The outer covering sheet 23 can be a piece of cloth or alternatively it can be a piece of leather. The foam part 22 is stuck on the inner covering sheet 21, and the outer covering sheet 23 is positioned over the foam part 22.

In assembly, first the inner covering sheet 21 is positioned over the loop-shaped part 1, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove 12 and secured to the loop-shaped part 1 by means of staples, and glue is applied over the inner covering sheet 21. Next, the foam part 22 is stuck on the inner covering sheet 21, and the outer covering sheet 23 is positioned over the foam part 22 and the loop-shaped part 1, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove 12 and secured to the loop-shaped part 1 by means of staples. Finally, an elongate insert 3 is tightly fitted into the loop-shaped groove 12 of the loop-shaped part 1 to embellish the circumferential edges of both the inner and the outer covering sheets 21 and 23, thus making the chair more pleasant-looking.

Therefore, when a person is seated on the chair, a major proportion of his/her bodyweight will be supported by that portion of the covering part 2 that is over the space 11 encompassed by the loop-shaped part 1, which is relatively soft and allows the sitter to comfortably rest on, preventing the sitter from having bad blood circulation and feeling numbness after he/she has been seated on the chair for a long period of time.

Referring to FIG. 6, a second preferred embodiment of a chair seat and back structure in the present invention includes a loop-shaped part 1, and a covering part 2′. The covering part 2′ is secured over the loop-shaped part 1, and it includes an inner covering sheet 21′, and an outer covering mesh sheet 22′ positioned over the inner covering sheet 21′. The covering part 2′ is positioned over the loop-shaped part 1, in tension and with circumferential edges of both the inner covering sheet 21′ and the outer covering mesh sheet 22′ being passed into a loop-shaped holding groove 12 of the loop-shaped part 1 and secured to the loop-shaped part 1 by means of staples. And, an elongate insert 3 is tightly fitted into the loop-shaped groove 12. Therefore, when a person is seated on the chair, he/she will be comfortably supported by the covering part 2.

From the above description, it can be seen that the chair seat and back structure of the present invention has the following advantages:

1. Because the inner and the outer covering sheets of the covering part are elastic and in tension, and they cover the space encompassed by the loop-shaped part, the covering part will be changed in its curvature by the sitter's body curvature. Consequently, the sitter will be comfortably supported on the chair, with his body touching the seat and back structure with increased area.

2. Because the covering part is positioned over the space encompassed by the loop-shaped part, air can travel through the seat and back structure very easily, preventing the sitter from feeling hot and uncomfortable after he has been seated on the chair for a long period of time. 

1. A chair seat and back structure, comprising a loop-shaped part with a space encompassed by an inner edge thereof; the loop-shaped part having a curvature and a loop-shaped holding groove near to a circumferential edge thereof; and a covering part secured over the loop-shaped part; the covering part including: (a) an inner covering sheet, the inner covering sheet being positioned over the loop-shaped part in tension, and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part; (b) a foam part stuck on the inner covering sheet; and (c) an outer covering sheet, the outer covering sheet being positioned over the foam and the loop-shaped part in tension, and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part.
 2. The chair seat and back structure as recited in claim 1, wherein an elongate insert is tightly fitted into the loop-shaped groove of the loop-shaped part to cover the circumferential edges of both the inner and the outer covering sheets.
 3. A chair seat and back structure, comprising a loop-shaped part with a space encompassed by an inner edge thereof; the loop-shaped part having a curvature and a loop-shaped holding groove near to a circumferential edge thereof; and a covering part secured over the loop-shaped part; the covering part including: (a) an inner covering sheet, the inner covering sheet being positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part; and (b) an outer covering mesh sheet, the outer covering mesh sheet being positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part.
 4. The chair seat and back structure as recited in claim 3, wherein an elongate insert is tightly fitted into the loop-shaped groove of the loop-shaped part to cover the circumferential edges of both the inner covering sheet and the outer covering mesh sheet. 